1. Field of the Invention
The present invention relates to a closure apparatus for a tank that can be used to contain various materials and that is preferably transportable to a remote location such as an offshore oil drilling or production platform. More particularly, the present invention relates to an improved tank closure apparatus that enables one of two dispensing openings to be used for gaining access to the tank interior, the larger opening being closable with a circular lid that is clamped in position with a ring, wherein the ring closure is cam operated with a locking lever and further providing a specially configured shroud that protectively covers the clamping ring while at the same time allowing access to the tank interior via the smaller opening.
2. General Background of the Invention
In the oil and gas well drilling and production industry, large tanks are often used to carry fluids to an offshore location such as an offshore oil well drilling or production platform. These tanks can carry any number of fluids that are used in the drilling or production process. One commercially available, known tank provides tank side walls, a tank upper end portion or top and two different closures or two different openings. These openings include a larger opening that is closed with a circular lid and held in place with a clamping ring. The closures also include a smaller opening that is at the center of the lid and that is in the form of a threaded outlet fitting.
Presently, the clamping ring is held in position with a bolted connection that gradually tightens the ring against a pair of annular ribs. Such a clamping ring is time consuming to install.